While I agree the plan is bad, for example, I don't like the across the board nature of the tax deduction, I think adding complexity to the tax code is a bad idea (I prefer the Fair Tax), and I would prefer everyone purchase their own insurance (or even better health savings accounts), I do believe Bush's plan exposes the utter hypocrisy of the left.
I have read two books on this recently, and they both say that the tax subsidy to employer provided health insurance is the first problem. It makes everyone think health care is cheaper than it is.